A conventional people counting device counts the number of persons in a target area by detecting the presence of persons by means of an infrared sensor or the like and incrementing a counter provided in the device if any persons are present.
In addition, the people counting device processes an image (input image) obtained by capturing a target area by means of an imaging device mounting an solid-state imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide Semiconductor), automatically detects an object in the input image, measures how many persons are present based on attribute information such as positions or movement paths of the object, and counts the number of persons in the target area by incrementing the counter provided in the device.
As one example, Patent Document 1 discloses a people counting device wherein a head model according to its head size (the ratio of the edge with respect to the size of the head model) expected in each portion of an image obtained when a person is imaged is set while shifting the position of the head model, a person's head portion included in the image is extracted based on the set head model, head portions extracted among a plurality of images included in a video are associated with each other, and the number of persons included in the video meeting predetermined conditions (time and area) is counted based on the number of trajectories of the associated head portions.